A bond through salmon, language, and grandmothers

Spirits of the Coast, published by the Royal BC Museum, brings together the work of marine biologists, Indigenous knowledge keepers, poets, artists and storytellers, united by their enchantment with the orca. Long feared in Western cultures as “killer whales,” and respected and honoured by Indigenous cultures as friends, family or benefactors, orcas are complex social beings with culture and language of their own.

Culture is defined as information or behaviour that is shared within a community and transmitted within or between generations through social learning. Culture has always been considered the unique hallmark of human societies. Until recently, the concept had never been ascribed to animals. However, as scientists are recognizing that decades of conservation strategies have failed to identify and account for key aspects of animal societies, this is rapidly changing. Lessons from fish to birds to mammals have shown the importance of social learning.

Some people’s first contact with animal culture might have been the stories of human guidance provided via ultralight aircraft to assist cranes and geese, raised in captivity, that learn their migration routes socially. It is seen in big horn sheep and moose that have been reintroduced to areas and then take generations to determine the seasonal availability of high-quality food. Many now know that a healthy elephant population requires elders to influence the behaviour and the development of younger animals. Even reef fish learn to identify predators without direct experience through socially transmitted information. These transfers of behaviour and knowledge lead to improved survival. The resilience of cultural diversity, along with genetics, appears key to the persistence and resilience of a wide range of animal populations.

The Southern Resident killer whales that ply the waters of coastal British Columbia and the Pacific Northwest are often distinguished from other ecotypes of killer whales based on their unique diet, dialect and culture. Vocal dialects, the differences in communication calls between neighbouring groups of whales, were one of the first recognized forms of culture in killer whales. Calves learn their dialect from their mothers and other family members; they retain it for life, and they pass it on to the next generation. Groups of whales with similar dialects are considered more closely related. Among the Southern Residents, the different pods (J, K and L) can be vocally distinguished based on the subtle differences in their calls. Researchers think these socially learned dialects might be important for female killer whales to distinguish males from outside their pods and thus avoid inbreeding. As a larger clan (J clan), the Southern Residents have calls that can be distinguished from those of the Northern and Alaskan Resident clans.

Culture in these whales is also observed through the presence of menopause, another biological process that we typically associate as a human trait. When Grannie, the matriarch of J pod, a Southern Resident killer whale family group, died in 2016, she was believed to be more than 90 years old and she hadn’t had a calf in more than 50 years. The researchers who viewed hundreds of hours of video footage found that in years when salmon abundance was low, the movements of whales were led by the post-reproductive females, for these were the whales with the greatest knowledge of where to look for salmon. The grandmothers are the repositories of ecological knowledge.

Viewing a map of the distribution of Resident killer whale clans on the Pacific coast of North America shows us an overlap with the distribution of another iconic symbol of the West Coast, Pacific salmon. From Northern California to Alaska, the range of these salmon-eating killer whales aligns with the spawning rivers of their primary prey.

“… to find chinook salmon, whales need to know more than where to look for them — they also need to know when to look.”  Tweet This!

The J clan of Resident killer whales occupy the most southern of the Eastern Pacific distribution, earning them their “Southern Resident” moniker. Their hunting grounds cover the migration routes of chinook salmon ranging from as far south as Monterey Bay to Vancouver Island and the Salish Sea in the north. But to find chinook salmon, whales need to know more than where to look for them—they also need to know when to look. More than any other salmon species, chinook throughout this range can be found returning to their natal rivers almost any month of the year. One river system, the Sacramento-San Joaquin River in California’s central valley, had runs of adult chinook every month of the year. The spring portion of these runs was often the largest and usually began in March. In the Central Valley, the first chinook to arrive in the spring run overlapped with the last arrivals of the winter run. Killer whales would have known that heading to California in the late winter was a good bet.

The biggest chinook river systems in North America were north of California’s Central Valley. The largest, the Columbia basin, drains much of western North America. The next largest is Canada’s Fraser River watershed, draining one quarter of British Columbia. Big rivers, with riverbeds of course gravel and cobble, host big chinook salmon. The gravel stream beds are used by spawning salmon as nurseries, where fertilized eggs buried by the female will lie protected in a redd (nest) just below the typical scour force of the river. Few eggs are crushed or washed away under typical conditions, and those hidden in the gravel receive the oxygen necessary to grow. The structure of the gravel beds is so ideal for the developing embryos, it’s as if the salmon designed it themselves. And indeed they did. The sheer size and number of the chinook salmon that moved huge volumes of rock, determining the river width, the gravel bars, and the overall structure of the river, engineered these spawning grounds. They designed the nursery with the right water depth, water velocities and gravel size. And for thousands and thousands of years, this strategy usually prevailed.

There are several possible reasons that Southern Resident killer whales evolved to select chinook over the other salmon species as their preferred choice of prey. They will eat other salmon, especially species like chum, steelhead and coho, but chinook are preferred. Chinook are the largest of all salmon and have the highest fat content. They are also available within Resident killer whale foraging grounds year-round. Their large size and high fat content make pursuing chinook a much more efficient expenditure of energy than pursuing smaller pink or sockeye salmon, even though smaller salmon are more abundant.

“Sharing is most common between a mother and her calf, but it is observed among all family members.”  Tweet This!

Large chinook can also be shared with family members, which is the typical way for the Southern Residents to consume them. Sharing is most common between a mother and her calf, but it is observed among all family members. The sharing of food reinforces the strong bonds that exist between family members, and feeding co-operation improves the chances of survival at an individual level and as a genetically unique matriline of Resident killer whales. Killer whale scientists think sharing may also limit greed, aggression and competition among family members.

So for thousands of years a Southern Resident killer whale lineage would have lived as a tightly knit unit with all the members of the mother’s family. An individual male whale could have a mother, grandmother, aunts and uncles, siblings, nieces and nephews. Living with his family, especially the presence of his mother, improved the likelihood that this male whale would survive. The family would travel and feed together, they would breed and socialize with other matrilines of whale families within the larger clan, they would teach young whales the communication calls unique to their family group, they would learn the timing and locations of salmon runs so that food could always be found, and they would pass the knowledge and the behaviours on to their offspring, and so forth through the generations.

But in the last 100 years, much of this has changed.

The context for the plight of Southern Residents today was under way by the mid-twentieth century. How many whales there were before this is unknown, but preliminary genetic examinations suggest a population of fewer than 200. Little was known about killer whales by the European colonists of the day. There was no distinction of ecotypes with different diets, let alone clans, pods, matrilines or individuals. There was no estimate of numbers. Killer whales did not enjoy the broad appeal they do today.

Removal of killer whales for the aquarium trade began in 1961. In total, 68 whales were taken from Southern BC and Washington waters, 47 of which were later assigned as Southern Residents. It wasn’t until after the practice ended in 1977 that awareness of their distinct behaviour, their small numbers, and their uniqueness as the Pacific coast’s most southerly population of salmon-eating killer whales emerged. But by this time, the damage was done.

Between the aquarium trade and an unknown number lost to gunshot wounds acquired in fishery conflicts, the population dropped below 70 whales. This had longlasting biological effects in terms of the small size of the remaining population and the lost generation; most of the removals were juveniles. The removals likely had cultural effects as well, in terms of the loss of strong bonds and the social cohesion that existed between family members. Anyone who has watched footage of the capture process might describe these as abductions.

Remarkably, there was a period at the end of the twentieth century when whale numbers were growing. Why they faltered after this is not clear, but a growing body of research is painting a picture of multiple threats that intensify when food is limited. Dr. John Ford at Canada’s Pacific Biological Station led the seminal work that established the relationship between Resident killer whales and chinook salmon. Ford and his team found that in years when the overall abundance of chinook was higher, birth rates were higher and mortality was lower. The opposite holds as well: when chinook abundance declined, so did birth rates, and mortality increased.

“The presence of vessels—from pleasure craft to fishing and whale watching boats to ferries and international freighters—can affect killer whale communication, behaviour and survival.”  Tweet This!

The declining abundance of chinook may not be the only factor affecting whales. chinook are also getting smaller, so more salmon are needed to meet a killer whale’s caloric demands and more energy is spent catching smaller fish. The year-round presence of migrating chinook is also becoming an artifact of the past. Serious declines in the spring and early summer abundance of chinook in the Salish Sea correlate with a decreased presence of Southern Residents in places and times where their occurrence was once very predictable.

Chinook numbers have declined, fish are smaller and spawning runs are less reliable at the same time that the Salish Sea has become a noisy and sometimes congested place. The increase in noise is especially troubling if you are an animal that relies on sound to hunt, navigate, find mates, and communicate. For a Resident killer whale, survival in a world where light is limited depends on the ability to hear and be heard far more than the ability to see. The presence of vessels—from pleasure craft to fishing and whale watching boats to ferries and international freighters—can affect killer whale communication, behaviour and survival.  

Scientific approaches to understanding the effects of underwater noise on a spectrum of marine organisms have advanced significantly in the last decade. It now appears that species less complex than whales are adversely affected by noise. Animals from cephalopods, such as octopus and squid, through to zooplankton and fish have sensitive apparatus for sensing their environment and enabling them to find food, communicate, swim, detect predators and survive. Noise can interfere with these critical functions. It can mask important communication, affect feeding, induce stress, inhibit development, cause injury, lower reproductive success, and even cause death. Air-gun pulses used in seismic arrays, for example, have been shown to kill zooplankton within a one-kilometre radius of a single blast.

Global and local studies on the world’s oceans indicate that underwater noise has increased by three decibels every 10 years since the 1950s. Decibels are measured on a logarithmic scale, so this translates to a doubling in ambient noise every decade for the last 70 years. Most of this noise is from increases in commercial shipping. The low-frequency sounds from ocean-going freighters and tankers can travel underwater for hundreds of kilometres, making this the principal source of ambient ocean noise. Oceanographer Dr. Scott Veirs has documented the noise from ships travelling through the Salish Sea to reach ports in the greater Vancouver and Seattle areas. These ships emit noise in a range of frequencies, including ones that overlap with frequencies used by killer whales. Even though the distance that high frequency sounds propagate from ships in the open ocean is generally less than 10 kilometres, once in the confined waters of the Salish Sea, mid- and high-frequency noise can quickly permeate the narrow straits and channels. And once in the Salish Sea, commercial ships are among dozens of vessel types and sources that make underwater noise ubiquitous.

“Among the Southern Residents, the different pods (J, K and L) can be vocally distinguished based on the subtle differences in their calls.”  Tweet This!

In killer whales, underwater noise and vessel traffic can have several pathways of effects. As the din of underwater noise grows, the area over which killer whales can hear and be heard decreases. This loss of communication space requires a whale to be closer to detect prey. The shorter the detection range, the less probable it is that the whale will find a salmon. Evidence also shows that killer whales respond to the noise by increasing the amplitude of their calls, requiring more energy to be heard.  

Noise may impart stress as well. The tragic events of 9/11 in 2001 led to a remarkable opportunity for scientists studying North Atlantic Right whales in the Bay of Fundy. A scat collection study was underway at the time, examining stress-related hormones in the whales. In the days following 9/11, underwater noise was significantly reduced from the grounding of ship and air traffic. Results from four years of data showed the six-decibel reduction in background noise post-9/11 corresponded to a decrease in stress hormones within the whales, linking noise to chronic stress.

Noise from vessels can also mask echolocation clicks killer whales use to detect and catch their prey. Killer whales distinguish chinook salmon from other salmon based on the sonar echoes bouncing off the salmon’s swim bladder, an organ that can reflect 90 per cent of the sound energy directed at it. A chinook’s swim bladder is smaller than that of a coho or sockeye and differs enough for orcas to detect and discriminate single chinook at distances of more than 100 metres. A hungry killer whale determines the species and size of the salmon, its direction and how fast it’s moving by sending rapid sequences of clicks and listening for their echo. Boat noise in the frequencies used by the whale can mask these critical echoes.

Lastly, the physical presence of a vessel in close proximity to a hunting killer whale can interfere with the chase. Dr. Rob Williams has studied the way boats can disrupt Resident killer whale behaviour and activities (like feeding, socializing, resting or travelling). His work indicates that the combination of physical and acoustic disturbance from the vessel can reduce feeding success by up to 25%. Estimates of vessel exposure for Southern Resident killer whales inside the Salish Sea suggest Southern Residents are in the presence of vessels 85% of the time and foraging in the presence of vessels 78% of the time. This translates to a 16% reduction in their food consumption when they are using their summer feeding grounds.   

When chinook are abundant, the consequence of lost meals to noise and disturbance can likely be endured, at least to some degree. The effort expended to catch a meal is critical when chinook abundance is low. From ending a five-minute food chase to avoid a boat that was originally 200 metres away, to the salmon that escaped because propeller cavitation masked echolocation clicks, it only takes a few minutes of interference at crucial times to lose a meal. Noise and disturbance reduces a killer whale’s hunting success, and for the Southern Residents, that means eating fewer salmon. Returning to Dr. Ford’s early conclusions: fewer chinook salmon mean fewer calves born and increases in adult mortality.

“Ensuring the survival of these whales in the Salish Sea isn’t about managing the ocean, it’s about managing humans.”  Tweet This!

Food-stressed whales also have to contend with another ugly side of the human footprint in the Salish Sea: pollution.

Chinook salmon should be providing the energy and nutrition to fuel survival and population growth, but they also deliver toxins accumulated from feeding in waters that drain the lands where eight million people live, work and recreate—the watersheds of the Salish Sea. Studies done on Puget Sound Chinook salmon have documented a suite of chemical contaminants that stretch from metals and toxins carried from cars and roads in stormwater, to pharmaceutical and recreational drugs delivered in wastewater. They also have industrial legacy pollutants (such as flame retardants, PCBs and DDT) that persist and bioaccumulate through food webs even though their use has been regulated. These fat-loving toxins accumulate in salmon, and then in whales through their salmon diet, building up in lipid-rich tissues like blubber and milk.

Food-stressed whales burn their fat reserves. When they do, they likely mobilize the persistent pollutants stored in their fat. In a female, contaminants stored in milk are transferred to a nursing calf. These pollutants can act as hormone mimics and unleash developmental effects in a foetus or a calf. Toxins in food-stressed whales are the likely reason for the excessively high rates of failed pregnancies in Southern Residents. Between 2008 and 2014, only 11 out of 33 pregnancies were successful, a failure rate of 69%. In 2017 and 2018 there were no successful calves at all. 

But lack of births is only part of the problem. A 2017 genetic study found that only two males fathered half the Southern Resident calves born since 1990 and that breeding within matrilines is occurring. This raises concerns for inbreeding, genetic diversity and fitness of the offspring. There is also concern for skewed sex ratios that favour males. 

But the more immediate problem is keeping existing whales alive. Since being listed as endangered under Canada’s Species at Risk Act in 2003, more than 50 whales have died, most of whom should have survived for much longer. Drone images of body condition collected by the Vancouver Aquarium and its US partners have revealed whales visibly malnourished, including the extreme loss of fat around the cranium that characterizes a condition called “peanut-head.” Rarely do whales recover once these signs appear. 

Combined, the lack of births and high mortality mean the population is not just failing to grow; it is declining at a rate that could spell extinction within 100 years. Some unique matrilines already show dead ends, with no reproductive females in the wings. Remember, however, it’s not just a numbers game—cultural knowledge, especially that held by mature females, is essential to everyone’s survival.  

The events that unfolded in the summer of 2018 galvanized many people to think about the Salish Sea, our human footprint and the iconic sentinels of these waters in a manner they had not before. The year started with 77 killer whales. The primary threats to recovery were widely known and conveyed in one sentence: reduced prey availability, physical and acoustic disturbance from vessels and contaminant exposure. Addressing these threats means confronting our human activities: fishing, whale watching, shipping, watershed planning, human consumption, population growth and climate change. Herein lies the inertia, in the aspirations of a large affluent human population and the consequential social and economic implications of any measures.

In the state of Washington, Governor Jay Inslee struck a special task force instructed to make recommendations for recovery measures. From Washington State’s perspective, struggling killer whales reflect the health of the Salish Sea. From forage fish like the herring that feed chinook salmon to pollutants draining into Puget Sound, the problems stem from the loss of ecosystem function, a concept that links ecosystem components (species) and processes to the quality and quantity of habitat. Ecosystem function is fundamental to the survival of endangered species, and its benefits accrue to far more than one species. 

Governor Inslee’s task force subsequently passed stronger laws to protect fish habitat and passed new toxin laws that allow for regulation of whole classes of household toxic chemicals. Environmental groups have called this the nation’s strongest legislation for consumer products. 

Canada’s steps toward threat reduction started after mounting public pressure over delayed recovery action, lawsuits, the growing profile of whale deaths and declining numbers forced action. The first federal measures were seasonal sport fishing closures in some places where Southern Residents feed. The goal was to reduce competition, noise and disturbance from fishing vessels in pursuit of the same chinook salmon. This was followed with more vessel measures. The distance boats had to maintain from a pod was increased to 400 metres. Sanctuaries were proposed (prohibiting vessels) and shipping companies were encouraged to slow down to limit their noise. Canada’s approach is species specific, linking threats to explicit times and areas. Although ostensibly comprehensive, these efforts fall short. Broadly, the times, areas and reductions are limited relative to what is likely necessary to effectively reduce stressors on whales. Importantly, most measures are not regulatory. That said, it marks a start.

Washington and Canada have taken different approaches to threat reduction. Both are necessary. What neither jurisdiction has accomplished is a way to increase chinook abundance, largely because viewpoints on why Southern Residents aren’t getting enough to eat are divided. Hatcheries are often touted as a solution, but putting more money and effort into hatchery production at a time when evidence indicates hatcheries are part of the reason wild chinook have failed to recover only deepens the problem. Southern Residents evolved to target large and old chinook salmon that spread their spawning migration from spring to fall. Hatcheries have failed to restore the old ages, big sizes, migration times and diversity of wild chinook salmon.  While this is worsened by fishing and climate change, new science suggests that the billions of hatchery salmon released annually into the North Pacific are overgrazing the commons. There simply isn’t enough food to go around, and chinook may be bigger losers in this game than, say, pink salmon. Whatever the mechanism, the evidence shows that the more hatchery fish there are, the less likely wild chinook can recover. 

But what chinook hatcheries do accomplish is keeping fisheries open, and herein lies a principal controversy in Southern Resident killer whale recovery.  From Alaska to the Pacific Northwest, more than a million chinook destined for Southern Resident feeding grounds are caught legally in marine fisheries. In addition, unknown numbers die from encounters with legal fisheries and as by-catch in non-salmon fisheries.   

Fish-eating seals and sea lions also are blamed for eating chinook. While pinniped numbers have grown since their protection in the 1970s, studies show that salmon generally, and chinook specifically, are a small proportion of their diet. Further, more seals have attracted their primary predator: the mammal eating Bigg’s killer whales, an effective presence for moderating seal numbers.   

In June of 2018, as Canada was announcing its first threat reduction measures, a 23-year old male whale from L pod named Cruiser (L92) was declared dead. He had not been seen since the previous fall, and as is typical, his body was never recovered and the cause of death undetermined. Population 76. In August, a juvenile whale named Scarlet (J50) was gravely ill. Named in honour of the toothmark scars on her dorsal fin, potentially from whales serving as midwives in the birthing process, Scarlet was one of the last whales born in 2015 before a three-year abeyance. As the health of Scarlet declined, unprecedented efforts to save this young female were initiated, including darting her with antibiotics and releasing live chinook from a boat in front of her. Despite this, Scarlet disappeared and her body was not recovered. Population 75.  

Many have wondered if these endangered whales have passed a critical threshold in their viability to recover. In 2017, a team of scientists working with the Raincoast Conservation Foundation published a study addressing this specific question: can they recover? The team concluded that with an increase in salmon these whales could recover, but the level of chinook required to do so was at the highest levels observed in the previous 30 years. Alternatively, if chinook abundance was not quite as high, but noise levels were cut in half, these endangered whales could reverse their decline and rebuild their numbers.

In July of 2018, a young mother from J pod named Tahlequah (J35) was ready to give birth. Her immediate family included her eight-year-old son, her mother, two siblings, and a niece. On July 18, Tahlequah gave birth to a female calf, but by the time observers from the Center for Whale Research arrived on site, the calf was dead. Tahlequah was repeatedly bringing the small neonate to the surface and taking long dives to retrieve it when it fell from where it was balanced on the rostrum section of her head. She continued to carry her calf for 17 days.

Loss is something Southern Resident killer whales know well. Tahlequah, for example, had lost her sister two years earlier in 2016 and her nephew shortly after that. Before this, she would have witnessed her sister lose a calf in early 2013. This was also not Tahlequah’s first lost calf. There was one, and likely two, before this loss. 

In his book Beyond Words, Dr. Carl Safina explores the tight bonds that lead to grief and emotion in animals, a topic that academics like Drs. Marc Bekoff and Barbara King have observed and documented for some time. King defines grief as a situation where surviving individuals who knew the deceased alter their behavioural routine. Regardless of the science, the inability of this mother to let go of her calf triggered a groundswell of emotion around the world, including in parents who recognize grief over a child. A remarkable documentation of these sentiments lives in a story and podcast by Seattle Times journalist Lynda Mapes.

Ensuring the survival of these whales in the Salish Sea isn’t about managing the ocean, it’s about managing humans. For a Resident killer whale, survival depends on the ability to hear and be heard far more than the ability to see. They now need us not just to see their plight and empathize, but to listen, and to act. Science does offer hope, indicating that we can put these whales on a trajectory toward recovery. Given this truth, we would all do well to reflect on our own ability to take responsibility for what is evident before us, as we also share a bond to this place, these salmon and these killer whales.  

As night fell on that summer day in 2018 when Tahlequah gave birth to her fated calf, she and members of her matriline approached Eagle Cove on the southwest side of San Juan Island. An island resident reported what they had witnessed that evening to the Center for Whale Research. It read as follows:

“At sunset, a group of 5-6 females gathered at the mouth of the cove in a close, tight-knit circle, staying at the surface in a harmonious circular motion for nearly two hours. As the light dimmed, I was able to watch them continue what seemed to be a ritual or ceremony. They stayed directly centered in the moonbeam, even as it moved. The lighting was too dim to see if the baby was still being kept afloat. It was both sad and special to witness this behaviour. My heart goes out to J35 and her beautiful baby; bless its soul.”

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